A conventional testing apparatus will frequently contain a sealed chamber that creates a controlled environment wherein testing may occur. It is often necessary to locate sensors within such a chamber to detect the conditions within the controlled environment. These sensors must be periodically calibrated for accuracy. Conventional apparatuses utilize several different configurations in an effort to provide access to the sensors for calibration. However, these conventional configurations suffer a number of drawbacks relating to sensor accuracy, operator safety, and accessibility.
Various attempts have been made to improve on the drawbacks associated with conventional testing apparatuses. Among these is U.S. patent to Evans et al., U.S. Pat. No. 3,536,370 issued Oct. 27, 1970; U.S. patent to Hugh et al., U.S. Pat. No. 5,792,427 issued Aug. 11, 1998; U.S. patent to Fedor et al., U.S. Pat. No. 5,206,518 issued Apr. 27, 1993; U.S. patent to Rathod et al., U.S. Pat. No. 6,946,652 issued Sep. 20, 2005; and an apparatus from Q-Lab Panel Corporation, called Q-U-V®.
Evans et al. is directed to an apparatus for carrying out processes in a controlled environment, and particularly for carrying out microbiological processes involving the production of dangerous pathogenic organisms. Evans et al. discloses an apparatus having a casing that includes three distinct chambers: a process chamber, a transfer chamber, and an instrument chamber. A transfer and exit liquid lock is fitted in the side of the casing. An internal wall of the lock juts into the transfer chamber and is open directly into the process chamber. A transfer well is let into the internal well from the transfer chamber. The arrangement is such that with sufficient liquid in the lock, the liquid seals the process chamber and the transfer chamber from each other and from the exterior of the casing. A sterilizing liquid is placed in lock and the transfer well is provided with a removable sealing cap to prevent loss of liquid by spillage.
An inlet lock is mounted in the casing to communicate between the exterior and the process chamber. The lock is a straight tube of bore sufficient for the passage of small containers or bottles. The lock contains an outer cap that may be removed to introduce instruments and sampling bottles into the process chamber. Control of the process is effected through the instrument and control panel located in the instrument chamber and glove ports. With the operator's left and right hands in the left and center gloves, the inner cap of the lock is removed and the object is transferred into the process chamber. Any container or instrument to be removed from the process chamber is dropped into the well associated with the transfer and exit liquid lock for retrieval by an operator. Thus, the structure and functionality of Evans et al. discloses a controlled environment apparatus wherein an inlet lock is used to safely introduce equipment into the process chamber and wherein a transfer and exit liquid lock is used to sterilize and safely retrieve equipment from a process chamber.
Hugh et al. describes a controlled atmosphere incubator and an improved incubator used to culture biological specimens. The controlled atmosphere incubator has an interior chamber surrounded by a heated water jacket. A glass access door of the chamber is directly heated by a clear, electrically conductive coating. The door is sealed against the perimeter of the opening by a readily replaceable gasket and is field reversible due to hinge mounting assemblies. The upper end of the cabinet includes a drawer for holding the various hardware components which are necessary in the implementation of the controlled atmosphere incubator. The drawer therefore allows easy maintenance and replacement of these components without necessitating the removal of panels. One such component located within the drawer is calibration circuitry for an infrared carbon dioxide sensor used by a microprocessor to calibrate the sensor. Thus, the structure and functionality of Hugh et al. appears to disclose a controlled atmosphere incubator having a drawer for isolation of hardware necessary for the control of the apparatus and calibration of the sensors.
Fedor et al. describes and relates to an accelerated weathering apparatus having a light source which irradiates onto specimens located in a specimen supporting wall which is located on the side of a test chamber. The output of the light source is controlled by independently adjustable control channels. The apparatus disclosed in Fedor et al. further includes light source detectors located on detector panels, which are located in the specimen supporting walls. The light source detectors detect irradiance existing in the test chamber and generate irradiance signals which are input to a controller. Each detector panel includes four openings, two of which are for ultraviolet detectors and two of which are for reference detectors. The light source detectors disclosed in Fedor et al. are only accessible by opening a pair of doors located on the sides of the apparatus. Thus, the structure and functionality of Fedor et al. appears to disclose test sensors that are mounted on detector panels located in specimen supporting walls, all of which are confined to the interior of the apparatus and accessible only by opening the apparatus doors.
Rathod et al. describes and relates to an apparatus for accelerated weathering testing specimens including discharge lamps as a concentrated light source for accelerating the deterioration of color, composition, and/or structure of test specimens. The apparatus further includes test modules that monitor the weathering test process from purportedly improved locations and detect the amount of irradiance to which specimens in the apparatus are exposed. The test modules are located in pockets formed within the doors for the test chamber such that the sensitive electronics of the modules are not exposed to the harsh environment within the test chamber. Rathod et al. further discloses a tank defining a test chamber, test modules, specimen holders, lamps, doors, and a moisture system. The doors have pockets formed therein for mounting test modules that house the test sensors and are replaceable with calibration modules housing calibration sensors for calibrating the system. Thus, the structure and functionality of Rathod et al. appears to disclose test and calibration sensors that are mounted in a pocket of a testing apparatus door and accessible without opening the apparatus door. A major disadvantage of this configuration is that the test and calibration modules fall out of the pockets when the door is opened resulting in an expensive accident. Another disadvantage is that the test and calibration modules must be removed from the door pockets before the door is opened. This is a serious hindrance and inconvenience to operation of the device.
The apparatus from Q-Lab Corporation describes and relates to an accelerated weathering tester designed to simulate the damaging effects of sunlight, dew, and rain on a test specimen. The apparatus includes a tank defining a test chamber, specimen holders, lamps, a main door, and a moisture system. The apparatus further includes florescent UV lamps to reproduce the effects of natural sunlight and a condensation mechanism to reproduce the effects of dew and rain. The Q-Lab apparatus also discloses irradiance sensors mounted on the specimen plane, behind the main door, that are only accessible by opening the main door. The main door further include safety interlocks. Thus, the structure and functionality of the Q-Lab Q-U-V accelerated weathering tester appears to disclose test sensors that are mounted on the specimen plane behind the main door.
While the above-discussed references offer unique configurations for accessing a sealed chamber, several drawbacks still exist.
With particular attention to Evans et al., it is noted that the transfer and exit lock contains a transfer well filled with sterilizing liquid. While this configuration is desirable for applications involving pathogenic organisms, it is ill-suited for applications involving sensitive electronic equipment. Specifically, removing sensitive electronic equipment, such as sensors, through a liquid-filled well would likely cause serious damage to the electronics, rendering them inoperable for their intended purpose.
A drawback associated with Hugh et al. is that the sensors are not mounted within the test chamber itself, but rather in the base of the moveable drawer. While this configuration makes the sensors accessible when the drawer is pulled out, it leads to serious sensor-alignment issues. Specifically, because the sensors are mounted on a moveable plane (the bottom of the drawer), it is difficult to ensure that the sensors obtain readings from the same disposition each time a reading is taken. This type of configuration negatively affects the sensors ability to return accurate readings.
With particular attention to Fedor et al. and the Q-Lab apparatus, it is noted that the test sensors are only accessible when an apparatus door is opened. Configurations requiring an apparatus door to be opened in order to remove or replace test sensors have several serious drawbacks. One such drawback is the possibility for operator injury. Utilizing either of these known configurations, an operator is required to first open an apparatus door in order to access the sensors. In so doing, the operator could be exposed to harmful ultra-violet radiation emanating from the apparatus light sources. For example, testing indicates that a conventional weathering apparatus, such as those disclosed in Fedor et al. and the Q-Lab apparatus, will breach the EN 61010-1 UV-safety standard within 30 seconds of operation when the apparatus door is in an open position.
Furthermore, and with respect to the Q-Lab device, the apparatus doors contain safety interlock mechanisms that must be manually defeated by short-circuiting or placing a magnet next to the proximity switch. Applying either of these methods to open the Q-Lab device's apparatus door would violate European Union safety regulations.
The configuration disclosed in Rathod et al. similarly suffers from several disadvantages described above. Additionally, other disadvantages of such a configuration include sensor alignment issues due to tolerance stackup, corrosion of connectors due to moisture breach, and difficult for operators to access the sensors.
Therefore, there is a need for an improved accelerated weathering apparatus that does not require the apparatus door to be open in order to access sensors, provides improved sensor accuracy, protects operators against harmful UV exposure, does not require a safety interlock to be defeated to access the sensors, protects connectors from corrosion, and has an ergonomic design facilitating convenient operator access to sensors.
The subject invention contemplates a new and improved accelerated weathering apparatus that overcomes all of the above-referenced problems, and others, and provides an optimal configuration for safely and conveniently accessing sensors.